The immediate goal of the candidate, Randy J. Wilson, DVM, is to complete a mentored training program in parasite immunopathogenesis research, which will culminate in both the PhD degree and the opportunity for continued postdoctoral study. Dr. Wilson's long-term goal is to become a principal investigator employing animal models and state-of-the-art methodologies to investigate the pathogenesis, therapy and prevention of malaria and other vector borne parasitic infectious agents. The research training program will be conducted in the Immuno-Parasitology Group Laboratory at Colorado State University, under the guidance of the sponsors, Dr. Anne Avery and Dr. Richard Titus. The candidate's program plan consists of laboratory and didactic training in contemporary molecular techniques and research methods, applied to an animal model of malaria. We propose to use an established murine model of malaria infection to investigate the early and late stages of the immune response to Plasmodium yoelii, with a focus on parasite antigens and their interactions with antigen presenting cells. Understanding this relationship and the ability of antigens and presenting cells to stimulate cell mediated and humoral immune responses through the progression of disease will be explored. The three specific aims to be addressed are: (1) to collect, isolate, purify and identify the parasite peptide antigens presented on different subsets of antigen presenting cells (macrophages, dendritic cells and B cells) during malaria infection. These Aim 1 experiments will involve peptide isolation and elution, high performance liquid chromatography and tandem mass spectrometry to identify and sequence the most prevalent parasite peptides. These sequences will be compared to known Plasmodium sequence data to identify the originating parasite protein; (2) to compare the cytokine profile and antibody isotype profile in infected mice, in response to the specific antigens MSP-C and MSP-N. Different parasite antigens are directing immune responses based on their handling by certain antigen presenting cell subsets, which then affects the type of cytokine profile that develops and the antibody isotype profile that is induced; (3) to study the ability of antigen presenting cells to process and present different types of parasite antigens at different stages of infection. This will be accomplished in Aim 3 experiments using two recombinant proteins (MSP-C and MSP-N) derived from Merozoite Surface Protein-I, a dominant parasite surface protein that is required for erythrocyte invasion during the asexual blood stage of malaria. We will also utilize T cell hybridomas produced with specificity for MSP-C and N. The results of these studies will provide new insights into the identity of predominant parasite peptides involved in malaria immune response. We will also gain insight into which peptides are involved during the progression of infection and what type of immune response they induce. This is information that may be important in developing effective treatment, control, and preventative measures in malaria.